As its name suggests, a personal digital assistant (PDA) can be like a pocket-sized secretary for the entrepreneur on the go. One little device can help you keep client appointments, e-mail staff from the road, surf the Web, and even record quick memos-to-self in the air. The right PDA can keep you organized and productive whenever and wherever you go.

“PDAs are ideal for mobile workers, whether it’s simply for walking around a campus or an executive on the road,” says Sean Ryan, a research analyst at IDC, the Framingham, Mass. technology research firm.

But these computers vary greatly in form, function, and price. The following is a look at a few decisions you need to make in order to hire the best “assistant” for your growing company.

Operating system

The first choice is which operating system to choose -- Windows Mobile/Pocket PC or the Palm OS. Each has its pros and cons: Many believe the Palm is a cleaner and simpler operating system with tens of thousands of downloadable programs and, after all, Palm was one of the pioneers of PDA technology. But the Pocket PC-based PDAs look and feel more like Windows and often include sync support for Microsoft Outlook and Exchange, popular business software.

Figure out which operating system best fits into your firm’s “ecosystem,” says IDC research analyst Ramon Llamas. That is, how well does it handle the programs that run your business?

Both the Palm and PocketPC operating systems can interact with Microsoft Outlook and Exchange, so that you can transfer information from your calendar or address book on your computer directly to your hand-held. “But Palm OS users may need to jump through more hurdles, such as downloading additional applications,” Llamas says.

Another consideration is whether everyone else in your firm has already standardized. “If everyone uses PocketPC, you might want to stick with that for two reasons: to easily acquire and share data between devices and to be consistent for your IT department so they don’t need to worry about handling multiple operating systems,” says Llamas.

Phone or no phone

Today, many PDAs, such as the BlackBerry, Treo and the latest HP iPaqs have an integrated cell phone. This convergence makes sense for business users. Not only will you carry around fewer gadgets but the two technologies can work together, allowing you to tap on a name in your address book and automatically dial their number. Another function allows you to chat with a customer via a headset or speakerphone and write down notes at the same time.

There are a few down sides. Those used to the teeny Motorola Razr may find a PDA cell phone too bulky. Your preferred cell carrier needs to support the PDA/phone hybrid you want. Finally, be aware if something happens to the PDA or cell phone functionality, you’re without both while it’s being repaired.

E-mail and Web access

Wireless e-mail and Internet access are other add-on services for PDAs that could enable workers to do quick searches from the car or e-mail colleagues from a client office. A worker with a PDA with e-mail and phone service can reply to an e-mail, call the person back using the phone, or add them to the address book with by pushing a few buttons.

“The multi-device question is an important one today for businesses,” Llamas says. “It can increase your productivity to have an all-in-one device, such as a BlackBerry.” For wireless data service, look for a PDA with integrated Wi-Fi or a high-speed cell phone connection, such as EDGE (GSM) or EV-DO (CDMA).

PDA buyers must assess the total cost of ownership before adding features. “The hardware could cost you anywhere from $100 to $400, and then there’s the $40 a month for a phone plan, another $60 or so for a data plan,” Llamas says. “All of a sudden it’s a lot of money.” Yet, hybrids could cut down on multiple devices -- no one needs a cell phone, laptop and hand-held organizer anymore.

Other considerations

PDAs come with nearly as many options as a new car these days. Here are extras for your line of work:

  • A built-in camera, audio recorder, or MP3 player may work for those who are in real estate or, say, entertainment.
  • Want a headset? Your PDA/cell phone needs integrated Bluetooth for hands-free communication.
  • PDAs integrated with GPS save buying a navigation system for the car.
  • Finally, security software is a must for a business PDA. “If you leave this PDA on the train and someone else picks it up,” Llamas says, “you have to make sure the data is inaccessible to others.”